For the sake of argument suppose the developer of a document-based app written in JavaScript running in the browser wanted to open and save files from and to the user's Dropbox folder. What's the best way to do that, given the new APIs that Dropbox has been releasing?

I see they have a Chooser. It looks like this can only be used to open files, not save them. Is that true?

It seems where Google wants you to use Google Docs to access their Drive space, Dropbox could build around an independent developer community that's potentially larger and more diverse than Google's. Is this their intent? Or will they create apps to compete with Google's?

What are developers doing? What's the best way of following new announcements in this area? If you are working on browser-based apps that integrate with Dropbox, please feel free to post a comment. I'd love to learn more.